1.Field of the Invention
This invention relates to the field of synchronizing clutches of the type that includes a sleeve having internal teeth that contact locking teeth on a synchronizer ring and clutch teeth on a gear wheel.
2. Description of the Prior Art
European Patent 00 05 645 describes a synchronizer for use in a manually operated automotive multiple speed transmission in which a synchronizer sleeve is displaceable axially on external teeth of a clutch hub and has internal teeth whose ends are brought into engagement with clutch teeth located on gear wheels that are journalled on the shaft that supports the clutch hub. The ends of the clutch teeth of the synchronizer sleeve include lateral flanks formed with recesses, which cooperate with the lateral flanks of the clutch teeth on the gear wheels to prevent spontaneous, unintended axial movement of the synchronizer sleeve while torque is transmitted between the gear wheel and the synchronizer hub.
The internal teeth of the synchronizer sleeve include a first group of holding teeth having recesses formed on both lateral flanks and another group of guide teeth whose members are formed with a recess on the lateral flank that faces the intermediate holding tooth. This arrangement prevents automatic axial movement of the synchronizer sleeve during torque transmission and achieves a more favorable disengaging movement during release of the engagement.
The clutches described in the European patent do not include means for synchronizing the rotational speed of the gear wheel and the synchronizer clutch nor do they consider the added complexity that locking of the synchronizer ring located between the clutch hub and the gear wheel has on the Process of engagement and movement of the synchronizer sleeve toward the gear wheel For example, if a synchronizing ring were located in the clutch assembly as described in the European patent, the locking teeth of the synchronizing ring attach to the recesses on the lateral flanks of the holding teeth of the clutch sleeve during movement of the sleeve toward the gear wheel after the speeds of the gear wheel and clutch hub have been substantially synchronized Because of this, the locking synchronizing ring is again pressed against the synchronizing cone on the gear wheel. This process impairs a smooth drivable connection between the synchronizing ring and the gear wheel and produces additional wear on the locking teeth of the synchronizing ring and the recesses of the holding teeth of the synchronizer clutch sleeve.